Function: Get an HTML img element representing an image attachment

Function: Get the URL of an image attachment.

Function: Scale an image to fit a particular size (such as ‘thumb’ or ‘medium’).

Function: Register a new image size.

Function: Check if an image size exists.

Function: Remove a new image size.

Function: Registers an image size for the post thumbnail.

Function: Gets an img tag for an image attachment, scaling it down if requested.

Function: Calculates the new dimensions for a down-sampled image.

Function: Retrieve width and height attributes using given width and height values.